Circuit-changing apparatus.



PATENTBD DEC. 29, 1903.

W. MEYER.

CIRCUIT CHANGING APPARATUS.

APPLICATION FILED OCT. 10, 1901.

no MODEL attorneys.

mi Noam: PETER: ca. PHOYO-LITNQ, WASHINGTON, n, c

UNITED STATES Patented December 29, 1903.

PATENT OEEIcE.

WILLIAM MEYER, OF CHICAGO, ILLINOIS, ASSIGNOR, BY MESNE ASSIGN- MENTS, TO STROMBERG-CARLSON TELEPHONE MANUFACTURING COM-' PANY, OF ROCHESTER, NEW YORK, A CORPORATION OF NEW YORK.

CIRCUIT-CHANGING APPARATUS.

SPECIFICATION forming part of Letters Patent No. 748,397, dated December 2 03- Application filed October 10, 1901. Serial No. 78.187. N model.)

To a whowt it may concern.-

Be it known that I, WILLIAM MEYER, a citizen of the United States, residing at Chicago, in the county of Cook and'State of Illinois, have invented a certain new and useful Improvement in Circuit-Changing Apparatus, of which the following is a full, clear, concise, and exact description, reference being had to the accompanying drawings, forming a part of this specification.

My invention relates to circuit-changing apparatus, and more particularly to that class of circuit-changing apparatus used in telephone systems, and has for its object the provision of improved means for efiecti'ng the operative interconnection between the vari ous circuits of a telephone-line.

My invention is of particular utility when used in connection with the cord-circuits of telephone systems whereby the operator may operatively associate a telephone-line with her operators listening set or with a calling apparatus, such as a ringing-generator.

My invention is designed to produce a circuit-changing device of this kind which may be of the simplest construction, which does not get out of adjustment, which is readily removable from the other appliances on a switchboard, and which may be easily repaired if in any way damaged. As is well known, circuit-changing keys when used in this connection must be so designed that they are self-locking in the listening position,while in the ringing position they automatically return to their normal position when released.

To this end my invention consists in the noveland improved construction of circuitchanging apparatus to be particularly 'described hereinafter in connection with the accompanying drawings, illustrating one embodiment thereof, in which- V Figure 1 is a view in elevation of my improved key. Fig. 2 is an end view thereof. Fig. 3 is a top view of my improved key. Fig. 4 is a detail view illustrating the manner of mounting the operating-lever, Fig. 5 is an end view of the lever mechanism.

Like characters of reference indicate like parts throughout the figures.

My improved key consists, in the embodiment thereof herein shown, of a cappingplate 1, adapted for mounting and insertion within the operating-table of a telephoneswitchboard, the capping-plate being of sufficient' size and strength to support all the circuit-changing mechanism and being provided with screw-holes 2 2, whereby the same may be secured to the said operating-table. The circuit-changing springs are mounted upon an inverted-L-shaped bar 3, secured to the capping-plate l by means of screws 4 4. In thus mounting the springs on one bar, vertically arranged in this instance, a key is produced which is simpleand made of a small number of parts. The circuitchanging springs comprise, in this particular embodiment, the generator-springs 5 5, the two sets of line-springs 6 6 and 7 7, and the springs 8 8, normally in electrical connection with the springs 6 6, but disengaged therefrom when said springs 6 are actuated to bring them into operative relation with the springs 5, whereby the line-circuit is broken at the point where the ringing-generator is connected to the line, so that a signal will be transmitted over but one subcircuit, as is well understood in the art, and also the operators lis- ;tening springs 99, placed adjacent to the isprings 7, an insulating-strip 10 being interposed to prevent normal electrical contact between the same. Insulating-strips 11 :11 are interposed, respectively, between the springs 5 and 6 and 6 and 8 for the purpose of preventing normal electric contact between the same except at the point where platinum contact-points may be inserted for this purpose. An insulating-strip 12 isplaced between the said springs B and 9 both for the purpose of mounting and preventing electrical contact between the same. The whole structure, comprising the sets of springs 5, 6, 7, 8, and 9 and the sets of insulating-strips ll, 11, 10, and l2,is secured to the L-shaped bar 3 by meansof bolts l3 l3, suitable washers l4 l4: and 15 15 being interposed for the purposes of construction. The springs 9 and 7 are normallynot electrically connected, the sets of springs 5 6 being likewise electrically discontinuous, whereas the sets of springs 6 and 8 are normally in electrical contact. A very compact and durable structure and secure mounting for the springsis thus secured,

the danger of getting out of order or of displacement by wear and tear being materially decreased.

The operative actuation of the keythat is, either bringing the springs 5 and 6 into electrical engagement or bringing the springs 7 and 9 into electrical engagementis efiected by means of a cylindrical-shaped actuating-button 16, of insulating material, which is suitably secured to an operating-disk 17, provided for this purpose, the disk 17 fitting into a groove provided in the actuating-button 16, as is well shown in the drawings. The disk 17 is pivotally mounted in the L- shaped bar 3 by means of a pin or shaft 18, whereby I dispense with the necessity of a movable escutcheon or plate to close the aperture which is necessary in the capping-plate 1 in order to have the lever pass therethrough, as the disk 17 will at all times retain its relative position with regard to the hole provided in said capping-plate, through which said disk may project. A lever 19, which may be secured to the disk 17 by means of screws, is employed for the purpose of efiecting an actuation of the disk 17, and thereby the actuating-button 16. The actuating-button 16 is held in place on the disk 17, preferably by means of a suitable screw 20. As mounted, the button 16 may be moved either to the right orleft, as desired, to efiiect the operative actuation of the springs, which are mounted below. The springs 9 are provided at their upper extremity with an inclined portion 21, which is arranged at such distance from the pivotal mounting of the disk 17 that when the button 16 is moved into engagement with said spring and rests upon said inclined section it will remain there-that is, it will be locked'in such position-thereby retaining the springs 9 in constant contact with the springs 7 unless the lever 19 is manually actuated in the reverse direction to remove the button 16 from engagementwith the said spring 9. The button 16 has also operative engagement with the set of springs 6 6, which springs are longer than either the springs 5 and 8; The button 16, however, impinges against one side of the said springs 6, which are bent into engagement with the springs 5 when the lever 17, as shown in Fig. 1, is moved toward the right. The resiliency of the said spring, however, tends at all times to push the lever normally back into the verdifficulty which has hitherto been apparent in keys of this nature-namely, the sticking of the actuating-button when actuated to operatively associate the ringing-keys so that a continued connection of the telephone-line with the ringing-generator is effected. It will be clear that by the construction which I employ this difficulty is overcome, as the contact-button 16 impinges against the side of the contact-spring, and thus has no possible chance of forming with it a position wherein said contact-button would be retained in any but its normal position.

It will thus be apparent that by means of my invention I materially decrease the space on the operators table which is required for the ringing and listening keys, as the springs of the said keys can be mounted close together,therebyreducingthewidth,the springs also being arranged vertically, whereby the length of the space which will be occupied by the said key in the operators table is reduced.

WVhile I have herein shown and particularly describedone embodiment of my invention, I do not wish to limit myself to the precise construction and arrangement as herein set forth; but, v

Having thus described my invention, I claim as new and desire to secure by Letters Patent 1. In a circuit-changing device, the combination with a capping-plate, of an L-shaped supporting-bar having its short arm secured to the lower side of said capping-plate, the long arm thereof extending perpendicularly downward, an opening through said short arm and said capping-plate, a disk pivoted to rotate longitudinally in said opening, an, actuating-handle normally extending upwardly from said disk, a cylindrical button of insulating material normally disposed below said disk and secured thereto, a mounting-block of insulating material extending directly below said button and parallel to and secured to the long arm of said supporting-bar, a straight contact-spring secured to said mounting-block at one end, the other end extending upwardly and disposed at one side of said actuating-button, another contact-spring secured to the opposite side of said mountingblock and extending straight upwardly, the end thereof being inclined outwardly and dis posed at the other side of said insulating-button, actuation of said handle causing said button to impinge against and move said straight spring outwardly, to be returned to its normal position by said spring upon release of the handle, an actuation of the handle in the opposite direction causing said button to engage the top of said inclined end of the long spring, to be retained in said position by said inclined end, substantially as described. I

2. In a circuit-changing device, the combination with a capping-plate, of an L-shaped supporting-bar having its short arm secured to the lower side of said capping-plate, the long arm thereof extending perpendicularly downward, an opening extending through said short arm and said capping-plate, a disk pivoted to rotate longitudinally in said opening, an actuating-handle normally extending upwardly from said disk, a cylindrical button of insulating material normally disposed below said disk and secured thereto, a mounting-block of insulating material extending directly below said button and parallel to and secured to the long arm of said support ing-bar, a pair of short, straight contactsprings secured at their lower end between said mounting-block and said supporting-bar and insulated from said bar and fromeach other, a long, straight contact-spring secured between but insulated from said short springs at its lower end, the otherend of said long spring being normally in contact with the innor short spring and extending beyond the short springs and disposed at one sidepf said cylindrical button, another long spring sec u red at itslower end at the other side of said mounting-block and extending straight upward, the end thereof being inclined outwardly and normally disposed at the other side of said cylindrical button, movement of the actuating-handle in one direction causing the cylindrical button to impinge against the long straight spring onthe inner side of the mounting-block, to be returned by said spring to its normal position upon release of the handle, and movement of the handle in the opposite direction causing the button to engage the top of the inclined end of the other long spring to be locked in such position, substantially as described.

3. In a circuit-changing device, the combination with a capping-plate,1 of a supportingbar 3, a disk 17, adapted to rotate longitudinally in an opening passing through said supporting-bar and said capping-plate, an actuating-handle extending upwardly from said disk, a button 16 of insulating material, secured to and below said disk, a mountingblock of insulating material 12, a straight spring 6 disposed through one side of said mounting-block, the end thereof being disposed at one side of the button 16, a spring 9 disposed at the other side of the mountingblock and having an inclined end 21 disposed at the other side of the button 16, actuation of the handle in one direction causing the button 16 to move spring 6 outwardly and to be returned bysaid spring to its normal position upon release of the handle,actuation of the handle in the opposite direction causing the button 16 to engage the top of the inclined end 21 to be locked in such a position, substantially as described.

In witness whereofl hereunto subscribe my name this 5th day of October, A. D. 1901.

WILLIAM MEYER.

"Witnesses:

MAX W. ZABEL,

HARVEY L. HANSON. 

